阿里云url获取图片SignatureDoesNotMatch

<Error>

<Code>SignatureDoesNotMatch</Code>

<span class="button collapse-button" style="-webkit-user-select: none; cursor: pointer; display: inline-block; margin-left: -10px; width: 10px; vertical-align: bottom; height: 10px; background-image: url("data:image/svg+xml,"); background-attachment: initial; background-size: initial; background-origin: initial; background-clip: initial; background-position: initial; background-repeat: initial;"><Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message>
<RequestId>57313DAC1A6B0AE72A97A3AC</RequestId>
<HostId>fg-file.oss-cn-hangzhou.aliyuncs.com</HostId>
<OSSAccessKeyId>zYHRAKo4kY4M4owG</OSSAccessKeyId>
<SignatureProvided>53nZyAPLqhr6cDtXYVdDq/Tlvls=</SignatureProvided>
<StringToSign>GET 1482262204046 /fg-file/test@100w.jpg</StringToSign>

<span class="button collapse-button" style="-webkit-user-select: none; cursor: pointer; display: inline-block; margin-left: -10px; width: 10px; vertical-align: bottom; height: 10px; background-image: url("data:image/svg+xml,"); background-attachment: initial; background-size: initial; background-origin: initial; background-clip: initial; background-position: initial; background-repeat: initial;"><StringToSignBytes>47 45 54 0A 0A 0A 31 34 38 32 32 36 32 32 30 34 30 34 36 0A 2F 66 67 2D 66 69 6C 65 2F 74 65 73 74 40 31 30 30 77 2E 6A 70 67</StringToSignBytes>
</Error>




后台计算出来的Signature的值是53nZyAPLqhr6cDtXYVdDq/Tlvls=


求助Signature的算法.